Username is already in use

[influence]

why it keep telling my members that username is already in use every time when they try to change their username and I check to see if their user names already existed but none of them were. Can you please tell me why? and how to fix it.

thanks

[Zachery]

why it keep telling my members that username is already in use every time when they try to change their username and I check to see if their user names already existed but none of them were. Can you please tell me why? and how to fix it.

thanks
Are you running the latest version?